Computer system and computer system management method

ABSTRACT

A computer system in which one or more host computers  30  having a FC (Fibre Channel) node port and one or more storage apparatuses  40  having a FC node port are coupled via a FC fabric. The storage apparatus acquires first information related to access control for controlling access to a relevant storage apparatus by the host computer. The storage apparatus, based on the first information, creates second information for defining the host computer that is able to access the relevant storage apparatus, and registers this second information in the fabric.

TECHNICAL FIELD

The present invention relates to a computer system and a computer systemmanagement method.

BACKGROUND ART

A data center couples together large numbers of servers and multiplestorage apparatuses using a Fibre Channel (FC) interface. For example,drops in apparatus performance, the end of an apparatus' service life,insufficient apparatus capacity, a dearth of network bandwidth, andsystem expansion will result in a data center replacing a server,network apparatus or storage apparatus with a new apparatus, adding anew apparatus, or removing an old apparatus from the computer system.

With conventional server virtualization technology, multiple virtualmachines can be operated in accordance with running virtualizationsoftware on a physical server. This server virtualization technologymakes it possible to temporarily suspend a virtual machine that isrunning on one physical server and migrate this virtual machine to thevirtualization software running on another physical server. Managementtasks related to the addition, replacement and removal of a server arecarried out using this technology.

As described above, in the prior art, it is possible to run multiplevirtual machines on a physical server. To operate a virtual machine thatis running on one physical server on another physical server, it ispreferable that is also be possible to virtualize Fibre Channel portsand to migrate these FC ports in virtual machine units.

Accordingly, technology (NPIV: N_Port Identifier Virtualization) forvirtualizing the name of an FC node port (N_Port), which is an FCprotocol expansion technique, is used. FC ports can be migrated invirtual machine units in accordance with using switches and host busadapters (HBA) that support NPIV.

In NPIV, it is preferable that a name identifier (WWPN: World Wide PortName), which is given to a virtual node port (VN_Port), not be changedbetween the pre-migration server WWPN and the post-migration serverWWPN. The reason for this will be explained. A zoning function, which isan FC switch security function, provides access control by using eitherthe WWPN, which is the N_Port name identifier, or a N_Port ID. TheN_Port ID is computed from a FC switch domain number or a physical portnumber.

A SAN (Storage Area Network) administrator, who differs from a serveradministrator, is the one who configures zoning. Therefore, changing theSAN zoning configuration in synch with server migration is a big jobbecause different administrators must exchange information with oneanother.

In addition, there are two types of FC zoning. One is zoning based onthe port identifier (N_Port ID). The other is zoning based on the nameidentifier (WWPN). In the case of the zoning based on the portidentifier (N_Port ID), migrating a virtual machine always requires azoning change. The reason for this is because the N_Port ID changes whenthe virtual machine is migrated to another physical server. Therefore,the transfer of frames related to the post-migration virtual machine isnullified by the zoning function based on the FC switch port identifier.

Therefore, in a case where a virtual machine is migrated betweenphysical servers, it is generally necessary for the user, whoadministers the computer system, to configure the FC port zoningfunction on the basis of the name identifier (WWPN). The user has theVN_Port (the virtual N_Port of the NPIV) take over a WWPN that is thesame as the pre-migration WWPN before and after the migration of thevirtual machine. In accordance with this, the user is able to migrate avirtual machine to a different physical server without changing the FCswitch WWPN-based zoning configuration at all (Non Patent Literature 1).

Most network equipment is configured redundantly. In a redundantlyconfigured network, after replacing a piece of network equipment (a FCswitch or the like) in the one system with a new piece of networkequipment, the piece of network equipment in the other system can alsobe replaced with the new piece of network equipment. This makes itpossible to achieve a higher performance and/or higher bandwidthnetwork.

The addition of a storage apparatus or a migration operation in astorage apparatus will be considered. In a case where there is afunction for the N_Port of a migration-destination storage apparatus totake over the WWPN of the migration-source storage apparatus, the usermay be able to carry out a migration from the migration-source storageapparatus to the migration-destination storage apparatus withoutchanging the zoning configuration of the FC switch.

However, in a first prior art, only control for migrating all of thevolumes that belong to the virtual N-Port of the migration source isdisclosed (Patent Literature 1 and Patent Literature 2). In the firstprior art, no method is disclosed for migrating only a portion of themultiple volumes belonging to either a single physical or virtual N_Portto either an arbitrary physical or virtual N_Port of themigration-destination storage apparatus. Similarly, in a third priorart, only control for migrating one volume belonging to themigration-source virtual N_Port is disclosed (Patent Literature 3).

However, in a conventional FC, all the domain switches belonging to afabric must provide distributed services possessing the routinginformation and the zoning in-number formation of the entire FC Fabric.In accordance with this, when there is an increase in the number ofdomains belonging to the fabric, the distributed services mustcommunicate and exchange information with each other. Therefore, thereis a limit on the number of domain switches that can be disposed in asingle fabric.

Accordingly, expanded standards for the FCoE (Fibre Channel overEthernet, Non Patent Literature 2) have been proposed (Non PatentLiterature 3 and Non Patent Literature 4). In an extended protocol, onlyone Primary FCF (FCoE Forwarder) is disposed inside a virtual domain(Virtual Domain), and distributed services are handled by the FCF. Inaddition, in an extended protocol, multiple FDF (FCoE Data Forwarder)are arranged inside the virtual domain. Each FDF is equipped with only aFC routing data transfer mechanism. The scalability of the number ofports of a single domain switch increases virtually in accordance withusing a single FCF and multiple FDFs.

The number of virtual domain ports can be increased in accordance withthe FDFs. The number of domain switches constitutes only one ControlFCF, which controls the FDFs. The number of domains belonging to thefabric does not increase. The Control FCF distributes routinginformation to each FDF. Therefore, each FDF is able to carry outrouting inside the FDF, and to communicate directly with the other FDFsthat belong to the same virtual domain.

The FC fabric zoning configuration is granular access control to the FCport. The FC zoning configuration is also necessary for curbing thepropagation range of the RSCN (Register State Change Notification),which is an FC topology change notification. The reason for this will beexplained below. When the FC port receives the RSCN from the fabric, theFC port must query the state of the fabric once again. For this reason,server I/O is temporarily interrupted. When expanding the propagationrange of the RSCN, the range of suspended server I/Os will expand,making it necessary to curb the propagation range using zoning.

LU granular access control is not possible with zoning since accesscontrol is in FC port units. Generally speaking, in a case wheremultiple LUs are associated with a single FC port in a storageapparatus, an LU that is accessed by a certain server can also beaccessed by another server. Accordingly, an LU granular securityconfiguration is required. A host group configuration is a task formapping a logical volume number (LUN: Logical Unit Number) inside astorage apparatus to a host logical volume number (H-LUN: Host LUN) thatcan only be seen by an identified host (Patent Literature 4).

Accordingly, a TDZ (Target Driven Zoning) protocol has been proposed inrecent years (Non Patent Literature 5 and Non Patent Literature 6). Inthe TDZ protocol, the storage apparatus port configures zoning in thefabric. Since this enables the user to carry out the zoningconfiguration when configuring the storage apparatus as well, the numberof FC fabric management processes is reduced.

CITATION LIST Patent Literature

-   PTL 1: U.S. Pat. No. 7,697,515-   PTL 2: U.S. Pat. No. 7,697,554-   PTL 3: US Patent Application No. 2010/0070722-   PTL 4: U.S. Pat. No. 6,779,083

Non Patent Literature

-   NPL 1: T11/02-338v1: NPIV Functionality Pro-file    http://www.t11.org/ftp/t11/member/fc/da/02-338v1.pdf-   NPL 2: Fibre Channel—Backbone—5—Revision 2.00 (page    81-124)http://www.t11.org/ftp/t11/pub/fc/bb-5/09-056v5.pdf-   NPL 3: T11/10-271v3: VA_Port FDF/Controlling FCF Protocols    http://www.t11.org/ftp/t11/pub/fc/bb-6/09-518v0.pdf-   NPL 4: T11/10-465v0: FDF Routing    http://www.t11.org/ftp/t11/pub/fc/bb-6/09-516v0.pdf-   NPL 5: T11/10-265v1: Register Peer Names    http://www.t11.org/ftp/t11/pub/fc/bb-6/09-516v0.pdf-   NPL 6: T11/11-001v0: Principal/Peers Zoning in FC-GS-7 (page    1-13)http://www.t11.org/ftp/t11/pub/fc/gs-7/11-001v0.pdf

SUMMARY OF INVENTION Technical Problem

It is difficult to apply the prior art in a case where a large number ofservers, storage apparatuses, FC switches (FC Domain Switch, FCF, FDF)are coupled together in a single huge FC fabric. The reasons for thiswill be described below.

When migrating a FC port (N_Port) from one storage apparatus to anotherstorage apparatus, server I/O (Input/Output) is interrupted. Therefore,the user must stop server I/O prior to FC port migration. Multiple LUsare associated with one port of the storage apparatus. Furthermore, acertain server accesses an identified LU. For this reason, at alarge-scale data center, the interruption of I/O for a FC port of onestorage apparatus interrupts the I/O of all the servers that access thestorage apparatus through this FC port.

Alternatively, in a case where a virtual machine is to be migrated,after temporarily suspending I/O, the virtual machine resumes I/O at themigration destination. Therefore, the problem described in theabove-mentioned FC port migration only occurs in the virtual machineduring migration, and does not occur in another virtual machine or aphysical server other than the migration-in-progress virtual machine.

The storage apparatus associates a large number of logical units (LU:Logical Unit) with one port. In a case where a port is to be migratedusing NPIV, it is difficult to separately migrate each logical unitassociated with this port to the migration-destination storageapparatus. As in the first, second and third prior arts, all of thelogical units belonging to an FC port must be migrated in line with themigration of this FC port.

Therefore, in the prior art, it is not possible to partially migrate aportion of a logical unit group belonging to either one physical orlogical FC port of a certain storage apparatus to another storageapparatus, resulting in low user usability.

It is supposed that different FC ports exist in themigration-destination storage apparatus, and that it was possible tocarry out a migration in volume units to the migration-destinationstorage apparatus. The port name identifier of the FC port of themigration-destination storage apparatus differs from the port nameidentifier of the FC port of the migration-source storage apparatus.Therefore, the user must add a new rule to the zoning configuration tomake it possible for the host and the FC port name identifier of themigration-destination storage apparatus to communicate. Since the FCfabric configuration must be changed in line with the volume migrationbetween storage apparatuses, management is made cumbersome. Furthermore,in the TDZ-related prior art (Non Patent Literature 4), neither meansfor managing zoning associated with a logical unit, nor means formanaging zoning associated with host group information (a group oflogical unit groups that can only be seen from an identified host) aredisclosed.

However, when migrating large numbers of either storage apparatus portsor server ports, the load is concentrated on the one control FCF. Thiswill be explained more specifically. The FC standard has a restrictionthat makes it impossible for two FC ports having duplicate portidentifiers (WWPN) to be logged in to the FC fabric at the same time.Therefore, in order to manage the state of the fabric consistently, thelogin-in-progress WWPN must be managed centrally, and the duplicate ofthe login-in-progress WWPN must be detected in accordance with the onecontrol FCF.

In a case where a server port is to be migrated, after logging thevirtual port (VN_Port) out, this virtual port must be logged in to themigration-destination physical server as the virtual port. Since thistraffic is transferred from the FDF to the one primary control FCF, thecontrol load is concentrated in the primary control FCF.

A port migration between storage apparatuses will be explained. Theremay be a case in which multiple logical units associated with a singlestorage port each communicate with different virtual servers. In thiscase, it is necessary to change the zoning configuration inside thevirtual domain and throughout the fabric. In the prior art (Non PatentLiterature 2 and Non Patent Literature 3), which extends the FCoEprotocol, the primary control FCF distributes the zone information toeach FDF. Therefore, the control load on the primary control FCFincreases.

With the foregoing in mind, an object of the present invention is toprovide a computer system and a computer system management method thatis able to reduce the management load.

Solution to Problem

A computer system of the present invention is coupled via a FC fabric toone or more host computers having a FC node port and one or more storageapparatuses having a FC node port, wherein the storage apparatusacquires first information related to an access control for controllingaccess to a relevant storage apparatus by the host computer, and, basedon the first information, creates second information for defining thehost computer that is able to access the relevant storage apparatus, andregisters the created second information in the fabric.

The first information constitutes a communication pair of the FC nodeport (storage port) of the storage apparatus and the FC node port (hostport) of the host computer. The second information is zoning informationrelated to a relevant target port capable of being sent from a targetport of the storage apparatus to the FC fabric. Furthermore, FCoE isalso included in the FC. The host port is the FC port of the hostcomputer. The storage port is the FC port of the storage apparatus.

The storage apparatus may comprise a migration-source storage apparatus,which constitutes the migration source of a migration-target resource,and a migration-destination storage apparatus, which constitutes themigration destination of the migration-target resource. Themigration-destination storage apparatus is able to acquire, eitherdirectly or indirectly, the first information from the migration-sourcestorage apparatus, create the second information based on the acquiredfirst information, and register the created second information in thefabric.

The first information may be first basic zoning information fordefining, from among the host computers, the host computer that is ableto access the migration-source storage apparatus, and the secondinformation may be second basic zoning information for defining, fromamong the host computers, the host computer that is able to access themigration-destination storage apparatus. The migration-destinationstorage apparatus can create the second basic zoning information bychanging information denoting the migration-source storage port of themigration-source storage apparatus within the information included inthe first basic zoning information to information denoting themigration-destination storage port of the migration-destination storageapparatus. The basic zoning information is information that becomes thebasis for creating zoning information for zoning control.

The first information may be created as host group information, whichassociates a host computer WWPN with a storage apparatus internal LU.

The second information may be zoning information related to a targetport that can be sent from a storage apparatus target port to the FCfabric. It is zoning information related to a target port, and is notthe zone information of the entire FC fabric.

The second information may be the second basic zoning information fordefining, from among the host computers, the host computer that is ableto access the migration-destination storage apparatus. Themigration-destination storage apparatus can create the second basiczoning information based on the host group information and informationdenoting the migration-destination storage port of the relevantmigration-destination storage apparatus.

In addition, the first information may be information related to a FCsecurity authentication protocol.

Furthermore, in a case where the migration-destination storage apparatusreads the first information from the migration-source storage apparatus,the first information may be host group information that is in themigration-source storage apparatus. Or, the first information may bePLOGI (port login) information from the host port. Or, the firstinformation may be FC security authentication information related to theFC port of the migration-source storage apparatus. Or, the firstinformation may be zoning information. This zoning information is a zoneset comprising the WWPN of a target port associated with themigration-target volume of the migration-source storage apparatus.

In a case where the migration-destination storage apparatus reads thefirst information from the migration-source storage apparatus, thesecond information may be created in the migration-source storageapparatus. That is, the configuration may be such that the secondinformation is not created by the migration-destination storageapparatus.

The present invention can also be understood as a management method ofthe computer system. In addition, the present invention can also beunderstood as a control program of the computer system. The controlprogram can be distributed via either a communication medium or astorage medium. In addition, the present invention can also beunderstood as a computer system switch.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram showing an overview of the entireembodiment.

FIG. 2 is a simple overview of a computer system in a case where a FCoEfabric is used.

FIG. 3 is a simple overview of the computer system in a case where aredundant configuration of the fabric in FIG. 2 is used.

FIG. 4 is a simple overview of the computer system in a case where a FCfabric is used.

FIG. 5 shows an internal configuration of a SKU (Stock Keeping Unit).

FIG. 6 is a block diagram of a FCoE Forwarder (FCF).

FIG. 7 is a block diagram of a FCoE Data Forwarder (FDF).

FIG. 8( a) shows the configuration of a FC frame, and FIG. 8( b) showsthe configuration of a FCoE frame.

FIG. 9( a) shows the configuration of a LUN field in a FCP_CMND, FIG. 9(b) shows a LUN device address format, FIG. 9( c) shows a LUN flat spaceformat, and FIG. 9( d) shows a logical unit addressing format.

FIG. 10( e) shows an extended LUN address format, FIG. 10( t) shows a3-byte extended flat space format, FIG. 10( g) shows a Well Known LUNformat, and FIG. 10( h) shows a W-LUN type code.

FIG. 11 shows a table for a management server to manage the internalLUNs of multiple storage apparatuses.

FIG. 12 shows the changes in the internal LUNs of each storage apparatusin a case where a volume has been migrated between storage apparatuses.

FIG. 13 is a VPD (Vital Product Data) format of SCSI showing a LUN nameidentifier, FIG. 13( a) shows a Device ID VPD information format, FIG.13( b) shows designator information stored in Device ID information,FIG. 13( c) shows a table classifying types of designator information,and FIG. 13( d) shows the format of a logical unit manufacturing number(Unit Serial Number VPD).

FIG. 14 schematically shows a storage apparatus virtualizationtechnique.

FIG. 15 is a simple overview of a computer system related to a firstexample.

FIG. 16 is a simple overview of a computer system related to a firstvariation of the first example.

FIG. 17 shows how to migrate a portion of the volumes from multiplevolumes associated with a single port.

FIG. 18 is a simple overview of a computer system related to a secondvariation of the first example.

FIG. 19 is a simple overview of a computer system related to a thirdvariation of the first example.

FIG. 20 is a simple overview of a computer system related to a fourthvariation of the first example.

FIG. 21 shows how to migrate a portion of the volumes from multiplevolumes associated with a single port together with host groupinformation.

FIG. 22 is a simple overview of a computer system related to a fifthvariation of the first example.

FIG. 23 is a simple overview of a computer system related to a sixthvariation of the first example.

FIG. 24 is a simple overview of a computer system related to a seventhvariation of the first example.

FIG. 25 is a simple overview of a computer system related to an eighthvariation of the first example.

FIG. 26 is control information for associating host group-related targetzoning information possessed by the storage apparatus.

FIG. 27 is a flowchart showing a first operation of the computer system.

FIG. 28 is a flowchart showing a second operation of the computersystem.

FIG. 29 is a flowchart showing a third operation of the computer system.

FIG. 30 is a flowchart showing a fourth operation of the computersystem.

FIG. 31 is a flowchart showing a fifth operation of the computer system.

FIG. 32 shows an example of the configuration of a virtual domain in theFCoE fabric related to a second example.

FIG. 33 is a flowchart showing the processing via which the FDFdistributes zoning information to other FDFs.

FIG. 34 is a ladder chart corresponding to the processing of FIG. 33.

FIG. 35 is a flowchart showing other processing via which the FDFdistributes zoning information to other FDFs.

FIG. 36 is a ladder chart corresponding to the processing of FIG. 35.

FIG. 37 shows an example of a case in which there are multiple virtualdomains in the fabric configuration of FIG. 32.

FIG. 38 is a flowchart showing the processing via which the FDFdistributes zoning information received from the storage apparatus toother FDFs and the FCF in the configuration of FIG. 37.

FIG. 39 is a flowchart showing processing related to a third example viawhich the FDF consolidates and distributes multiple pieces of zoninginformation.

FIG. 40 is a ladder chart corresponding to the processing of FIG. 37.

FIG. 41 shows a zoning information request message, FIG. 41( a) showsthe request, and FIG. 41( b) shows a portion of the entry for FIG. 41(a).

FIG. 42 is a zoning information response message, FIG. 42( a) shows arequest format, and FIG. 42( b) shows a response format.

FIG. 43 is a ladder chart showing a method for distributing zoninginformation between multiple fabric switches belonging to a domain.

FIG. 44 is a ladder chart showing a method for the control FCF todistribute zoning information held by the control FCF to the respectiveFDFs.

DESCRIPTION OF THE EMBODIMENT

The embodiment of the present invention will be explained below based onthe drawings. This embodiment, as will be explained hereinbelow,provides a method for migrating a virtual resource for reducing themanagement load of a virtual resource migration. Furthermore, theconfiguration shown in FIG. 1 is merely one example of the presentinvention, and the present invention is not limited to the configurationshown in FIG. 1.

An overview of this embodiment will be explained by referring to FIG. 1.Furthermore, the present invention is not limited to the configurationshown in FIG. 1. FIG. 1 shows a process via which the storage apparatuscreates zoning information (more precisely, basic zoning information,which will be explained further below) and registers this zoninginformation in the FC fabric, and a process via which the FC zoninginformation is distributed within the FC fabric.

The present invention does not have to comprise all of these processes.A configuration such that the storage apparatus only creates andregisters the zoning information in the fabric is also included withinthe scope of the present invention. A configuration such that the zoninginformation is distributed from one FDF to another FDF is also includedwithin the scope of the present invention.

FIG. 1 shows an overview of the entire configuration of the computersystem. In the computer system, for example, multiple host computers30(1), 30(2), 30(3) and multiple storage apparatuses 40(1), 40(2), 40(3)are coupled to enable two-way communication via a fabric 50.

Furthermore, when no particular distinction is made, the host computers30(1), 30(2), 30(3) will be called the host computer 30, and the storageapparatuses 40(1), 40(2), 40(3) will be called the storage apparatus 40.The same will hold true for the FDF and so forth described furtherbelow. The host computer 30 may be called the server 30 in the examplesexplained below.

The fabric 50 is configured as a FCoE fabric, but may also be configuredas a FC fabric 60 as will be explained below. The fabric 50 comprisesone FCF 10 and multiple FDFs 20(1), 20(2), 20(3). The FCF 10 comprises aname server, and centrally manages names inside a domain. The respectiveFDF 20 control the transfer of frames. The respective FDF 20 comprisezoning information.

Although omitted from FIG. 1 for expediency sake, each storage apparatus40 comprises multiple ports. Each port can be associated with multiplelogical volumes 43. In this embodiment, either one or multiple arbitraryvolumes from among the multiple volumes associated with a certain portof the storage apparatus 40(1) is/are migrated to the storage apparatus40(3) and are associated with the port of the storage apparatus 40(3).Host group information is associated with the migration-target volume.The host group information related to this volume is also transferred tothe storage apparatus 40(3) in line with migrating a portion of thevolumes from the storage apparatus 40(1) to the storage apparatus 40(3).A configuration in which multiple volumes are associated with one port,and a portion of the volumes from thereamong is migrated will bedisclosed using FIGS. 17 and 21 described further below.

A case in which a volume 43 is migrated from the storage apparatus 40(1)to the storage apparatus 40(3) as the migration-target resource will beexplained. The migration-source storage apparatus 40(1) comprises accesscontrol information (TDZ A) for managing the port (host FC port) of thehost computer 30 that is allowed to access the storage RC port.Depending on the situation, the host group information may be usedinstead of this access control information. The host group informationis for managing a LUN that can only be seen by the host computer 30. Theaccess control information is equivalent to either “first information”or “first basic zoning information”. The host group information isequivalent to the “first information”. The host group informationdenotes the relationship between the storage apparatus host WWPN and theinternal LU accessed by the host port.

The migration-destination storage apparatus 40(3) acquires from themigration-source storage apparatus 40(1) target zoning information thathas been created in the migration-source storage apparatus 40(1) (S1).Or, the migration-destination storage apparatus 40(3) acquires from themigration-source storage apparatus 40(1) the host group information ofthe migration-source storage apparatus 40(1) that has been configuredbeforehand by an administrator (S1 a).

As will be explained further below, there are multiple acquisitionmethods. For example, the migration-destination storage apparatus 40(3)may read the access control information from the migration-sourcestorage apparatus 40(1). The access control information may be sent fromthe migration-source storage apparatus 40(1) to themigration-destination storage apparatus 40(3). Or, themigration-destination storage apparatus 40(3) may acquire FC fabriczoning information from the fabric 50, and may acquire informationdenoting which host computer the migration-target volume iscommunicating with.

Furthermore, the host computer performs a port login (PLOGI) withrespect to the port of the storage apparatus. Therefore, the port WWPNof the host computer that is currently in the process of carrying out anaccess can also be collected from the port login information. Exchangingthis port login information between the storage apparatuses also makesit possible to create the zoning information that is to be configured inthe FC fabric.

The migration-destination storage apparatus 40(3) creates new accesscontrol information based on the information acquired from themigration-source storage apparatus 40(1) (S2). The new access controlinformation is equivalent to either “second information” or “secondbasic zoning information”.

This will be explained by giving access control information (TDZ A)defined using WWPN as an example. The migration-destination storageapparatus 40(3) changes the storage port number (storage port A)included in the information (TDZ A) acquired from the migration-sourcestorage apparatus 40(1) to the storage port number (storage port A1) ofits own apparatus.

The migration-destination storage apparatus 40(3) sends the accesscontrol information (TDZ A) with the rewritten storage port number tothe FDF 20(3) that is directly coupled to the storage port identified bythis storage port number (S3). The FDF 20(3) is equivalent to a“coupling-destination second switch”.

The FDF 20(3) asks the FCF 10 for a name resolution for the information(TDZ A) received from the migration-destination storage apparatus 40(3)(S4). The FCF 10 uses the name server to convert the WWPN to the N_PortID, and returns this N_Port ID to the FDF 20(3) (S4). In accordance withthis, zoning information that serves as “third information” iscompleted.

The FDF 20(3), which created the zoning information, sends this zoninginformation to each of the other FDFs 20(1), 20(2), where it is stored(S5). Specifically, the zoning information is distributed to all theFDFs 20 that are able to receive a frame that is transferred to themigration-destination storage apparatus 40(3). The zoning information isdistributed to the other FDFs 20(1), 20(2) from the FDF 20(3) thatcreated this zoning information without going through the FCF 10.

Distributing the zoning information to the other FDFs, for example,signifies sending and registering the zoning information in the otherFDFs to either execute zone control or to complete preparations forexecuting zone control.

Thereafter, the volume 43 is migrated from the migration-source storageapparatus 40(1) to the migration-destination storage apparatus 40(3)(S6). There are multiple methods for migrating a volume.

One method is to create a virtual logical volume (hereinafter, virtualvolume) 43V inside the migration-destination storage apparatus 40(3),and to associate this virtual volume 43V with the migration-sourcelogical volume 43.

When the host computer 30 accesses the virtual volume 43V, themigration-destination storage apparatus 40(3) accesses the logicalvolume 43 inside the migration-source storage apparatus 40(1) and readsthe data. In other words, the storage space of the logical volume 43 andthe storage space of the virtual volume 43V are associated on aone-to-one basis. The migration-destination storage apparatus 40(3),upon receiving a command from the host computer 30, converts thiscommand to a migration-source storage apparatus 40(1) command and sendsthis converted command to the migration-source storage apparatus 40(1).The migration-destination storage apparatus 40(3) receives the commandprocessing result from the migration-source storage apparatus 40(1) andresponds to the host computer 30.

Another volume migration method is to send the data of the logicalvolume 43 in the migration-source storage apparatus 40(1) to all thelogical volumes created in the migration-destination storage apparatus40(3). After completing the data migration, the migration-source volume43 may be deleted or may be kept as-is.

A case in which, during volume 43 movement, the migration-destinationstorage apparatus 40(3) creates basic zoning information and registersthis information in the fabric 50 at volume migration time has beendescribed, but the configuration may also be such that the basic zoninginformation is registered in the fabric 50 at another time. Furthermore,the migration-target resource is not limited to a single volume 43, butrather may be multiple volumes that have been grouped together, or astorage port.

In this embodiment, which is configured like this, in a case where aresource is to be migrated between storage apparatuses 40, the storageapparatus 40 can automatically modify the basic zoning information forcreating the zoning information, and register this basic zoninginformation in the fabric. Therefore, in this embodiment, managementproblems can be lessened and usability improved.

When virtual machines or volumes (LU) are frequently migrated, a largenumber of storage apparatuses must distribute zoning information to thefabric. In the past, transactions were numerous due to the fact that theFCF distributed the zoning information to multiple FDFs. By contrast, inthis embodiment, distributing the target zone information received fromthe storage port from the FDF that received this information to themultiple other FDFs reduces the number of FCF transactions. As a resultof this, the size of the virtual domain, which specifies all of themultiple FDFs controlled by the FCF, can be increased. In addition, nocontrol bottlenecks occur in the fabric no matter how frequently avirtual machine or volume is migrated.

Example 1

A first example will be explained by referring to FIGS. 2 through 29.FIG. 2 shows the configuration of the computer system in a case wherethe FCoE fabric is used.

A SKU (Stock Keeping Unit), for example, is a unit that is configured in19-inch rack units. The SKU 1 is equipped respectively with a networkapparatus 20, a server 30 (a host computer 30), and a storage apparatus40 in accordance with customer system requirements. The SKU is the unitfor shipping a tested apparatus from the factory.

The computer system of FIG. 2 comprises a fabric 50 that carries theFCoE protocol. The fabric 50, for example, is configured as an Ethernetfabric (Ethernet is a registered trademark). Two FCFs 10 p and 10 s,which comprise a redundant configuration, are coupled to the fabric 50.

The FCF 10 p is the FCF for carrying out primary control. The FCF 10 sis a secondary FCF, which is on active standby. The primary FCF 10 psends its own information to the secondary FCF 10 s information, andsynchronizes this information. Each SKU1 is provided with a FCoE framerouting function-specific FDF 20. The primary FCF controls therespective FDFs. Each FDF transfers frames and carries out accesscontrol based on the routing information and the zoning information fromthe FCF.

FIG. 3 shows a simple overview of the computer system in a case where aredundant fabric configuration is used. The fabric 50 is a communicationnetwork comprising a configuration having redundancy. Specifically, thefabric 50 comprises dual switches FCF 10 p, 10 p, 10 s, 10 s. Even if afailure occurs in the one switch, the other switch operates in itsplace. Therefore, even if a failure should occur, all the SKU1s canaccess the network. Because of redundancy, multiple FDFs 20 are disposedinside the SKU1.

FIG. 4 shows a simple overview of the computer system in a case where aFC fabric 60 is used in the configuration of FIG. 3. FIG. 4 separatelycomprises fabric 50, but this fabric 50 has been omitted from thedrawing. In the FC fabric 60, multiple FC switches 61 through 68 areconnected in mesh fashion, and even if one of the FC switches shouldfail, either the server 30 or the storage apparatus inside the SKU1 willbe able to communicate with either the server 30 or the storageapparatus 40 inside the other SKU1.

FIG. 5 is an example of the internal configuration of the SKU. In theSKU1, for example, there are disposed a server 30, a storage apparatus40 and a network apparatus 20. The example of FIG. 5 shows FDFs 20,which support both Ethernet (registered trademark) and FCoEcommunications, as network apparatuses. Furthermore, the network isshown as comprising a redundant configuration.

Each configuration element of FIG. 5 will be explained. The server 30serving as the “host computer”, for example, has at least one virtualmachine (VM) 33 and multiple E_Node MACs 31. The E_Node MAC (FCoE NodeMedia Access Control) is a lossless Ethernet physical port. The E_NodeMAC 31 carries out the login process, which is a procedure forparticipating in the FC fabric. Furthermore, the server 30 is describedhere as comprising a virtual machine 33, but the present invention canalso be applied to a configuration in which a virtual machine does notexist.

The E_Node MAC 31, upon logging in to the FC Fabric, can create one ormore VN_Ports (virtual node port) 32 instances. This instance creationfunction will be called a FC NPIV (N_Port ID Virtualization).

Each VN_Port 32 and virtual machine 33 may correspond on a one-to-onebasis. Allocating a VN_Port 32 for each virtual machine 33 makes itpossible to take over and migrate the port identifier (WWPN: World WidePort Name) of the VN_Port 32 in a case where the virtual machine 33 onthe physical server 30 migrates to another physical server.

Taking over the WWPN of the VN_Port 32 makes it possible to migrate thevirtual machine 33 to another physical server 33 without changing thezoning, which is the FC fabric ACL (Access Control List). This does awaywith the need to change the network configuration at the time of virtualmachine migration, thereby making it possible to lessen the managementload.

The storage apparatus 40 of FIG. 5 has an E-Node MAC 41 the same as theserver 30. The E_Node MAC 41, upon having logged in to the FC fabric,creates a VN_Port 42 instance. One or more VN_Port 42 instances arecreated with respect to one E_Node MAC 41.

The storage apparatus 40 can comprise multiple physical volumes 43 andvirtual volumes 43V (refer to FIG. 1). The virtual volume 43V is coupledto a logical volume of the other storage apparatus. The data of thevirtual volume 43V is actually stored in this coupling-destinationlogical volume.

The FDF 20 comprises multiple FCF MACs 21, which are physical ports. TheFCF MAC 21 supports two types of ports 22 and 23 corresponding to thecoupling destination. A VA_Port 23 is an extension port for extendingbetween the FCF 10 or FDF 20 and the switch. A VF_Port 22 is a fabriccoupling port for coupling to the E_Node MAC and creating a VN_Portinstance. The FDF 20 will be explained further below.

FIG. 6 is the internal configuration of a FCoE forwarder (FCF) that isable to control the FDF. The FCF 10 has a FC switch element 15. The FCswitch element 15 is coupled to the respective ports 12, 13, 14, andcarries out FC D_ID (Destination ID) routing.

The FC switch element 15 is coupled to a distributed service 100. Thedistributed service 100 detects and retains the information of therespective ports 12, 13, 14, topology management of the FC fabric, anddevice information.

The distributed service 100 is configured from programs 102, 104, 106and databases 101, 103, 105. The distributed service 100 is realized bythe processor inside the FCF 10 executing a program stored in thememory. The same holds true below for the other apparatuses, but theprocessor and memory have been omitted from the drawings.

The FCF 10 has multiple types of ports. A VE_Port 12 is an extensionport for forming a switch-link with the FCF 10, which has been givenanother domain number. A VF_Port 14 is a port for coupling to theE_Node. The VE_Port and VF_Port are not able to reside together insidethe same FCF MAC 11. A VA_Port 13 is a Virtual Adjacent Port for forminga switch-link for coupling the FCF to the FDF that is under the controlof the FCF.

The distributed service 100 of the FCF 10 comprises a program and adatabase for managing the topology of the FC. A name server 102 and aname server database 101 store either the port name identifier (WWPN) orthe node name identifier (WWNN) of the node port that is logged in tothe fabric.

In addition, the name server 102 comprises a program for allocating anode port identifier (N_Port ID) corresponding to the WWPN when the nodeport logs in to the fabric.

The name server database WI comprises a table, which includes a WWPN, aWWNN, and a N_Port ID. As other entries, the database 101 has a symbolicname, a FC4-type, a FC-4 feature, and so forth. For example, when aquery is made with respect to the name server 102, an initiator queriesa device, which is supporting FCP (Fibre Channel over SCSI Protocol) asthe FC-4 type. In accordance with this, the initiator acquires a targetport capable of SCSI communication. This name server query method mayalso be a method for querying a device that has the FC-4 feature targetport attribute.

A fabric configuration service (fabric configuration server) 104 and afabric/virtual domain database 103 manage the topology of the fabric andmanage the port link state of each switch.

The switch-link makes it possible to acquire the coupling state of aswitch by exchanging messages notifying the link state. The switch-linkmakes it possible to acquire either information as to whether or not acoupling exists or the coupling state of the partner device that iscoupled to each switch by acquiring a list of port states. In accordancewith this information, it is possible to detect the topology of theentire fabric.

A fabric zoning service (fabric zoning server) 106 and a fabric zoningdatabase 105 merge the zoning configuration information of therespective switches in the fabric, and retain all the zoninginformation.

The fabric zoning database 105 here comprises two types of databases1050 and 1051. One is a zoning database 1050 with respect to a localvirtual domain controlled by the FCF 10. The other is a zoning database1051 with respect to another domain that is under the control of anotherFCF. Zoning operations will be described further below.

FIG. 7 shows the internal configuration of the FDF 20. The FDF 20, forexample, comprises a FCF MAC 21, a VF_Port 22, a VA_Port 23, a FC switchelement 25, and a FDF local service 200. Explanations that duplicatethose of FIG. 6 will be omitted.

The FDF local service 200 is a service for transferring a controlmessage from the VF_Port 22 of the FDF 20 to the FCF 10, and forreceiving a control message from the FCF 10 and configuring the FDF 20.The FDF local service 200 is configured from a program 204 and databases201, 202, and 203. The FDF local service 200 is realized in accordancewith the processor inside the FDF 20 executing a program stored in thememory.

The FDF local service 200 will be explained in detail. A controlmessage, which is received from either the VF_Port 14 or the VA_Port 13,is received by a message transfer program 204. The message transferprogram 204 converts the received control message to another message asneeded, and sends this converted message.

A virtual domain database 201 stores virtual domain internal routinginformation, which is held in a N_Port ID Range Allocation messagereceived from the FCF 10.

A N_Port ID allocation database 202 stores a correspondence table ofN_Port IDs and WWPNs. When the E_Node that is coupled to the VF_Port 22logs in to the fabric, a N_Port ID is allocated from the FCF 10. Thatis, the N_Port ID allocation database 202 is a name server database,which corresponds to a VN_Port created when the E_Node coupled to theFDF 20 logs in to the fabric. This database 202 holds only localinformation, and does not comprise information with respect to anotherFDF 20 or information with respect to another domain.

A zoning database 203 holds zoning information, which is distributedfrom the FCF 10, the FDF 20, or the VN_Port of the E_Node. The zoningdatabase 203 is divided into two databases.

One is a local FDF zoning database 2030, which holds zoning informationdistributed from either the FCF or the E_Node VN_Port. The other is azoning database 2031, which is distributed from another FDF in the samevirtual domain. The use of these databases will be explained furtherbelow.

Refer to FIG. 8. FIG. 8( a) shows the configuration of a FC frame. FIG.8( b) shows the configuration of a FCoE frame. In the case of the FC, aD_ID 81 is used to determine the routing destination of the FC frame. Inthe case of the FCoE, an Ethernet Header part is removed by the VF_Port,the VE_Port, or the VA_Port, and the FC frame is selected. Then, the FCswitch element performs routing using the D_ID 81 inside the received FCframe.

Either the FCF or FDF VF_Port, VE_Port, or VA_Port has a FCF MACcomprising a unique MAC Address. For this reason, a DA 83 and a SA 84are changed each time a frame passes through either the FCF or FDF, andthe frame is routed through the fabric 50 in accordance with the MACAddress.

Refer to FIGS. 9 and 10. FIG. 9( a) shows a LUN field structure of aFCP_CMND. FIG. 9( b) shows a LUN device address format. FIG. 9( c) showsa LUN flat space format. FIG. 9( d) shows a logical unit addressingformat. FIG. 10( e) shows an extended LUN addressing format. FIG. 10( f)shows an extended flat space format. FIG. 10( g) shows a Well Known LUNformat. FIG. 10( h) shows a W-LUN type code.

FIG. 9( a) is the structure of a FCP_CMND LUN field. An informationunit, such as FCP_CMND and FCP_DATA is stored in the FC Data field ofthe FC Frame. The FCP_CMND format has an 8-byte LUN field for specifyinga SCSI logical unit number. A number of formats are defined in the LUNin accordance with the address method field.

FIG. 9( b) shows the LUN device address format. This format can specifya 1-byte Target/LUN. FIG. 9( c) shows a LUN flat space format. Thisformat can specify a 14-bit flat LUN.

FIG. 9( d) shows a logical unit addressing format. This format iscapable of specifying both a SCSI bus Target/BUS number and a LUN. Thisis a configuration in which multiple initiator ports (bus number fields)are disposed under a certain SCSI device target port, these initiatorports comprise multiple target ports (Target fields), and multiple LU(LUN fields) are disposed under these target ports.

FIG. 10( e) shows an extended LUN addressing format. The role of thisformat will change in accordance with the extended address method field,and this format will be classified into either the format of FIG. 10( f)or FIG. 10( g).

FIG. 10( f) is an extended flat space format. This format extends theconfiguration of FIG. 9( c). The extended flat space LUN stores a valueobtained by combining a storage apparatus management number, a storageapparatus target port number, a LUN and so forth as information relatedto a volume migration between storage apparatuses. This makes itpossible to use a management server 70 (Refer to FIG. 15) to check todetermine which storage apparatus created the volume to be migratedbetween storage apparatuses. This configuration will be explainedfurther below using FIGS. 11 and 12.

FIG. 10( g) shows a Well Known LUN format. FIG. 10( h) shows a table ofW-LUN type codes. A case in which the W-LUN code is 0x01 denotes aspecial logical unit that responds to REPORT LUNS. For example, having aREPORT LUNS W-LUN makes it possible to migrate a logical unit with LUNnumber 0 to another storage apparatus. In addition, for example, as willbe explained further using FIG. 17, it is also possible to extend thisfunction to configure a W-LUN 86 for managing target port zoning foracquiring zoning information between storage apparatuses.

FIGS. 11 and 12 are tables showing the status of an internal LUN of eachstorage apparatus managed in accordance with the management server.These tables are management information used for tracing a volumemigration between storage apparatuses.

The table T10 shown in FIG. 11 shows the state prior to migrating thevolume between the storage apparatuses. FIG. 12 is the state subsequentto migrating the volume between the storage apparatuses as indicated bythe three LUNS L21, L22 and L23, which are shown in L10 of FIG. 11.

Each table T10 and T20, for example, comprises a storage name columnC10, a storage ID column C11, a total number of LUs column C12, and alist of LUNs column C13. The name of a storage apparatus is configuredin the storage name column C10. Information for identifying each storageapparatus is configured in the storage ID column C11. A total value ofthe number of LUs of the storage apparatus is configured in the totalnumber of LUs column C12. The LUNs of the storage apparatus areconfigured in the form of a list in the list of LUNS column C13.

Using the extended LUN format makes it possible to manage which storageapparatus created a LUN. Specifically, for example, storing a storage ID92 in the first byte of the extended LUN makes it possible to determinethat the LUN of storage apparatus A has been migrated.

For example, volume (00 00) of storage apparatus A shown in L10 of FIG.11 is migrated to storage apparatus B as indicated by L21 of FIG. 12. Anextended LUN (D2 0A 00 00) is configured with respect to thepost-migration volume. 0A denotes that the volume has been migrated fromstorage apparatus A.

FIG. 13 is SCSI VPD (Vital Product Data) formats showing a LUN nameidentifier taken over in line with the migration of a storage apparatusvolume. FIG. 13( a) shows a device ID VPD information format. FIG. 13(b) shows designator information stored in the device ID information,FIG. 13( c) shows a classification table of designator information typeinformation. FIG. 13( d) shows a logical unit manufacturing number (UnitSerial Number VPD) format.

The volume name identifier (also called the World Wide LU Name) must betaken over when a volume is migrated between storages. This is because,in order to determine that the same volume is accessed from multiplepaths, path switching software and the like for managing multiple pathsuse the volume name identifier to determine that the volume is the samevolume. Therefore, even though the port name identifier of the storageapparatus may differ, in a case where the name identifier of theaccessible volume ahead is the same, the path switching softwarerecognizes that multiple paths are able to access the same volume. Thepath switching software recognizes the volumes having the same nameidentifier as a single volume capable of being accessed via multiplepaths.

The volume name identifier can be created by combining the designator(for example, includes the ASCII code of the name of the vendor) of FIG.13( a) and the apparatus serial number of FIG. 13( d). This makes itpossible to create an identifier that is unique world wide. Therefore,this identifier is used as the volume name identifier. The managementterminal for managing multiple storage apparatuses can also assign aunique volume name identifier virtually. The volume name identifier mayalso be created by a stand-alone storage apparatus using the apparatusmanufacturing number.

When migrating a volume between storage apparatuses, the volume nameidentifier is added as the volume name identifier of the virtual volumeof the other storage apparatus. Therefore, a volume having the volumename identifier is created once again by the source storage apparatus,and managed so that the volume name identifier is not duplicated.Accordingly, the same volume name identifier as that of the migratedvolume is managed in accordance with the management information T20 ofFIG. 12 until deleted.

FIG. 14 schematically shows a storage apparatus virtualizationtechnique. The one storage apparatus 40(D) is the migration-destinationstorage apparatus. The other storage apparatus 40(S) is themigration-source storage apparatus.

An initiator port 420(B) of the migration-destination storage apparatus40(D) is coupled to a target port 420(A) of the migration-source storageapparatus 40(S). A target port 420(C) of the migration-destinationstorage apparatus 40(D) is coupled to a port of the host computer 30 viathe fabric.

The migration-source storage apparatus 40(S) is coupled subordinate tothe migration-destination storage apparatus 40(D) like this. Thephysical volume 43 of the migration-source storage apparatus 40(S) isassociated with the virtual volume (V-VOL) 43V disposed in themigration-destination storage apparatus 40(D).

The migration-destination storage apparatus 40(D), upon receiving acommand from the host computer 30 targeted at the virtual volume 43V,creates a command with respect to the volume 43 of the migration-sourcestorage apparatus 40(S).

The migration-destination storage apparatus 40(D) sends this command tothe migration-source storage apparatus 40(S), and writes/reads datato/from the volume 43. The migration-destination storage apparatus 40(D)sends the result of command processing to the host computer 30. Thismakes it possible for the host computer 30 to transparently access thevolume 43 of the other storage apparatus 40(S) subordinate to themigration-destination storage apparatus 40(D). Furthermore, in thefollowing explanation, the host computer may be abbreviated as host.

FIG. 15 shows a storage apparatus virtualization technique specific tothis embodiment. The host 30 can communicate directly with each storageapparatus, and can carry out access via a virtual volume. An overview ofthe processing will be explained hereinbelow. The processing will beexplained in detail further below using FIGS. 25 through 29.

A case in which an actual volume 43 of the migration-source storageapparatus 40(S) is mounted to a virtual volume 43V of themigration-destination storage apparatus 40(D) will be explained. Thehost 30 accesses the volume 43 by way of the target port 420(A) of themigration-source storage apparatus 40(S).

Zoning is applied to the FC fabric. Zoning (Zone 1) is configured usinga pair comprising the port name identifier (hereinafter WWPN) of thehost 30 initiator port and the WWPN of the target port 420(A) of thestorage apparatus 40(S).

A number of configurations are required before mounting the volume 43 ofthe migration-source storage apparatus 40(S) to the virtual volume 43Vof the migration-destination storage apparatus 40(D).

First, zoning (Zone 2) must be configured using the WWPN of theinitiator port 420(B) of the migration-destination storage apparatus40(D) and the WWPN of the target port 420(A) of the migration-sourcestorage apparatus 40(S). This is to enable the exchange of data betweenthe migration-source storage apparatus 40(S) and themigration-destination storage apparatus 40(D).

Second, zoning (Zone 3) must be configured using the WWPN of the targetport 420(C) of the migration-destination storage apparatus 40(D) and theWWPN of the initiator port of the host 30. In accordance with this, dualzoning (Zone 2 and Zone 3) must be configured for the host 30 to accessthe actual volume 43 via the virtual volume 43V.

A management server 70 is used to configure the zoning with respect tothe communication path between the storage apparatuses. The managementserver 70 manages multiple storage apparatuses in the computer system.The configuration may also be such that the storage apparatus registerszoning information in the fabric without using the management server 70.

As will be described further below, the configuration may be such that azoning list, which is a list of host ports that the relevant target portaccesses from the target port, is disposed in either the initiator port420(B) of the migration-destination storage apparatus 40(D) or thetarget port 420(A) of the migration-source storage apparatus 40(S), andthe storage apparatus registers the zoning information in the fabric.

In the prior art, the FC fabric administrator has to cooperate with thestorage administrator to change the fabric zoning. In this example, thestorage apparatus 40(D) configures a zone in the fabric so as to enablethe host 30 to access the virtual volume 43V via the target port 420(C).As will be described further below, there are multiple methods via whichthe storage apparatus acquires information (creation-source information)as to which host is accessing a volume, which is necessary for creatinga target zone that is configured in the target port.

In FIG. 15, in a case where a volume has been migrated from the storageapparatus 40(S) to the storage apparatus 40(D) (that is, a case in whichthe virtual volume 43V and the actual volume 43 have been coupled), thehost 30 path is switched. The communication path between the host 30 andthe migration-source storage apparatus 40(S) is made passive. Thecommunication path between the host 30 and the migration-destinationstorage apparatus 40(D) is made active. The timing of the communicationpath switchover is not limited to the above steps. As long as there is amechanism for maintaining the consistency of the data between the twostorage apparatuses, the above-mentioned two paths may be activesimultaneously.

Furthermore, the method for migrating the volume between the storageapparatuses is not limited to the method that uses a virtual volume. Forexample, the method may be such that an unused volume is prepared in themigration-destination storage apparatus 40(D), and the data of themigration-source storage apparatus 40(S) volume is copied to this unusedvolume. Various methods for switching the host 30 paths are also known,but will not be mentioned in particular.

FIG. 16 shows a first variation. The first variation also enables thehost 30 to transparently access the volume 43 of the migration-sourcestorage apparatus 40(S) via the virtual volume 43V of themigration-destination storage apparatus 40 (D).

In the first variation, zoning information is allocated to the targetport 420(C), which is the physical port of the storage apparatus 40(D).In this example, a single zone is used for access control with respectto all the volumes belonging to the target port 420(C).

A zone is applied using the initiator port 32 of the host 30 and thetarget port 420(C) of the migration-destination storage apparatus 40(D).Therefore, the target port 420(C) describes the WWPN of the host 30initiator port 32 in the zoning list 44 configured in the FC fabric. Thezoning list 44 is equivalent to either the “first information” or the“first basic zoning information”.

Configuring the target port 420(C) zoning information (zoning list 44)in the fabric makes it possible for the initiator port 32 of the host 30to access a local volume and the virtual volume 43V in themigration-destination storage apparatus 40(D).

The W-LUN 45 shown in FIG. 16 is the Well Known LUN, which was explainedin accordance with FIG. 10( g) and FIG. 10( h). For example, preparingthe REPORT LUNS W-LUN makes it possible to migrate LUN number 0 as well.

LUN number 0 is a special LUN, which responds with a list of all the LUNnumbers belonging to the target port in accordance with the SCSI REPORTLUNS command. For this reason, in a case where the LUN number 0 does notexist, the existence of the other LUNs is not known.

Accordingly, in FIG. 16, providing W-LUN 45 makes it possible to respondto the REPORT LUNS. In accordance with this, the host 30 is able tonormally acquire a list of LUNs of LUN1 and later even without LUN0 in acase where only LUN0 has been migrated and no longer exists but theother LUN numbers (#1 and later) do exist (a case in which the #0 doesnot exist and there is a gap in the LUN numbers).

FIG. 17 is an example clarifying the configuration of FIG. 16. In FIG.17, multiple volumes (Vol A) and (Vol Z) are associated with the port420(A) of the storage apparatus 40(S). FIG. 17 shows how one of thesevolumes (Vol A) is migrated to the storage apparatus 40(D). In thisexample, it is possible to migrate only a portion of the ports like thiswithout migrating all of the volumes linked to the port.

Different examples with respect to the retention method and applicablescope of the zoning information (Zoning List: accessible listenumerating initiator WWPNs), which the target port configures in thefabric, will be explained below using FIGS. 18 through 25. Consequently,duplicate explanations will be omitted.

FIG. 18 shows a second variation. In this example, too, the host 30transparently accesses the volume 43 of the migration-source storageapparatus 40(S) via the virtual volume 43V of the migration-destinationstorage apparatus 40(D).

In the second variation, the zoning information 44 is allocated in unitsof virtual target ports of virtual SCSI BUS numbers of the storageapparatus. A virtual initiator port 421 is provided within themigration-destination storage apparatus 40(D).

The SCSI BUS C comprises a bus number 0. The SCSI BUS C corresponds tothe local volume of the migration-destination storage apparatus 40(D).Multiple virtual initiator ports 421 can be disposed in themigration-destination storage apparatus 40(D). Under the virtualinitiator port 421, access is carried out in accordance with the busnumber of the SCSI BUS A.

Multiple virtual target ports 422 are disposed under the SCSI BUS A. Atarget number is used to specify a virtual target port 422. Target A ofSCSI BUS A can have multiple virtual volumes 43V. A virtual volume 43Vis specified using a logical unit number.

These bus numbers, target numbers, and logical unit numbers areequivalent to the respective fields of the LUN definition format ofeither FIG. 9( c) or FIG. 9( d). For example, the migration-sourcestorage apparatus 40(S) is allocated within the range of either thevirtual target port or the virtual initiator port. This enables thetarget port 420(A) and the volume 43 of the migration-source storageapparatus 40(S) to be virtually associated as-is in themigration-destination storage apparatus 40(D).

FIG. 19 shows a third variation. In this example, too, the host 30transparently accesses the volume 43 of the migration-source storageapparatus 40(S) via the virtual volume 43V of the migration-destinationstorage apparatus 40(D).

The zoning information 44 is allocated in storage apparatus LUN units.In the pre-migration state, as shown in the right side of FIG. 19, thezoning information C of the LUN C, which is the local volume, isconfigured in the fabric.

When the volume 43 is migrated from the migration-source storageapparatus 40(S) to the migration-destination storage device 40(D), thezoning information 44 of LUN A for controlling access to the virtualvolume 43V is stored in the storage apparatus 40(D).

For this reason, the target port 420(C) registers information thatcombines the zoning information 44 and the zoning information C in thefabric. This makes it possible for the host 30 to access both the localvolume A and the virtual volume 43V.

FIG. 20 shows a fourth variation. In this example, too, the zoninginformation 44 is configured in units of virtual ports. This variationis equivalent to a configuration that expands the configurationexplained using FIG. 16 in proportion to the number of virtual ports.

In a case where there are multiple hosts 30, it may be desirable tospecify a volume that can be seen by each of the hosts and a host LUN(H-LUN). Consequently, a storage apparatus function called a host groupis used.

The host group is a function for mapping an internal LUN to the H-LUN inhost units. An accessible volume and a LUN number (H-LUN) for lettingthe host see this volume are associated with respect to the initiatorport name identifier (WWPN) of a specific host in host group information46.

The WWPN of the initiator port of the host, which must access thisvolume, is listed in the host group information 46. Therefore, the hostgroup information 46 can be used to create the zoning information 44.The information of the host group information 46 and the zoninginformation (zoning list) 44 will be explained further below using FIG.26.

FIG. 21 is an example clarifying the configuration of FIG. 20. In FIG.21, multiple volumes (Vol A) and (Vol Z) are associated with a singleport 430(A). Only one of these volumes (Vol A) is migrated from thestorage apparatus 40(S) to the storage apparatus 40(D). The host groupinformation related to this volume (Vol A) is taken over by the storageapparatus 40(D) in line with the migration of the volume (Vol A).

FIG. 22 shows a fifth variation. In this example, too, the host 30transparently accesses the volume 43 of the migration-source storageapparatus 40(S) via the virtual volume 43V of the migration-destinationstorage apparatus 40(D).

The zoning information 44 is allocated in storage apparatus virtual portunits. The storage apparatus can create either one or multiple virtualport instances (VN_Port X) in either the physical FC port (FC PN_Port)of the target port or the NPIV under the FCoE Node (E_Node).Consequently, the zoning information 44 is allocated in virtual portunits.

FIG. 23 shows a sixth variation. This variation is equivalent to aconfiguration that expands the configuration explained using FIG. 18 inproportion to the number of virtual ports.

In this variation, multiple virtual initiator ports 421 are associatedwith the storage apparatus virtual port 42. Multiple virtual targetports 422 are created in the virtual initiator port 421. The zoninginformation 44 is allocated in virtual target port units.

FIG. 24 shows a seventh variation. This variation is equivalent to aconfiguration that expands the configuration explained using FIG. 19 inproportion to the number of virtual ports. In this variation, the zoninginformation 44 is allocated in units of the volumes allocated to thevirtual port 42 of the storage apparatus.

FIG. 25 shows an eighth variation. This variation is equivalent to aconfiguration that expands the configuration explained using FIG. 20 inproportion to the number of virtual ports. The host group is configuredby grouping together the volumes that have been allocated to the virtualport 42 of the storage apparatus. In this variation, the zoninginformation 44 is allocated in units of this host group.

In the explanations given using FIGS. 17 through 25, a virtual volume43V is also provided in addition to a local volume in themigration-destination storage apparatus in line with the migration of avolume. The LUN number must be extended due to repeated volumemigrations like this among the large number of storage apparatusesincluded in the computer system.

Consequently, a LUN is identified in accordance with the extended flatspace LUN format explained using FIGS. 10( e) and 10(f). This makes itpossible to store the LUNs of virtual volumes migrated from multiplestorage apparatuses inside a single storage apparatus.

Furthermore, it is also possible to change the virtual volume 43V to thelocal volume inside the migration-destination storage apparatus 40(D) bycopying the data of the migration-target volume 43 of themigration-source storage apparatus 40(S) to the virtual volume 43V.

FIG. 26 is control information for associating target zoning informationwith a host group of a storage apparatus. FIG. 26( a) is a host grouptable T30. The table T30 is an example of the host group information 46.FIG. 26( b) is a target zoning information table T40. The table T40 isan example of the zoning information 44.

The host group information T30, for example, correspondingly manages ahost group number C30, a storage WWPN list C31, a host WWPN list C32, aninternal LUN number C33, a host LUN number C34, and a target zone groupnumber C35.

The host group number C30 is information for identifying each hostgroup. The storage WWPN list C31 shows the port (WWPN) of a storageapparatus that is accessible as a host group. The host WWPN list C32 isa list of ports (initiator port WWPN) of identified hosts.

The internal LUN number C33 is information for identifying a volume(including both a physical volume and a virtual volume) in an accessiblestorage apparatus. The host LUN number C34 is a LUN number (H-LUN) in acase where a host is allowed to see a volume. The target zone group C35is the number of a target zone group for associating with the targetzoning information (FIG. 26( b)).

As described hereinabove, the initiator port WWPN (C31) of the host thatrequires access is listed in the host group information T30. Therefore,the host group information can be used to create the zoning informationT40 shown in FIG. 26( b).

Furthermore, the configuration may be such that a pair comprising atarget port and host initiator port in the migration-source storageapparatus is acquired from the FC fabric. In accordance with this,zoning information (FIG. 26( b)) suited to the migration-destinationstorage apparatus 40(D) can be created in the migration-destinationstorage apparatus 40 (D). This will be explained further below usingFIGS. 29 through 31.

FIG. 26( b) is the table T40 of target zoning information. The targetzoning table T40, for example, correspondingly manages a target zonegroup number C40, a storage WWPN list C41, and a host WWPN list C42.

The target zone group number C40 corresponds to C35 of FIG. 26( a), andassociates the host group information T30 with a target zone group. Thestorage WWPN list C41 is a list of port name identifiers (WWPN) of thestorage apparatus. Furthermore, since the migration port is theinitiator port, both the initiator port and the target port can bestored in the C41. The host WWPN list C42 is a list of accessible hostport name identifiers (WWPN).

The steps for registering the zoning information in the fabric will bedescribed further below using FIGS. 32 through 40. The message for thestorage apparatus port to configure a zone in the fabric will bedescribed further below using FIGS. 41 and 42.

The configuration for associating the target zoning information T40 withthe host group information T30 in FIG. 26 will be explained. Theconfiguration described in FIG. 26 can be used with the configurationsof FIG. 20 and FIG. 25.

For example, in a case where either a portion of the entries are cutfrom the table T30 of FIG. 26( a), or a new entry like the SCSI BUS IDis added to the table T30, the configuration of FIG. 26 can be used withanother configuration besides those of FIGS. 20 and 25. Explanations ofthese variations will be omitted since they can be easily inferred fromthe contents described in FIG. 26( a).

The host (server) port here is logged in to the target port of thestorage apparatus. The migration-source storage apparatus is able tostore port login information (PLOGI). The target zoning information foraccessing the migration-destination storage apparatus volume may becreated from the port login information (PLOGI) possessed by each portof the migration-source storage apparatus.

The host issues a SCSI command INQUIRY to the volume. Or, the hostspecifies a LUN, which has been allocated to the volume, and issues aread I/O, write I/O, or other SCSI command. The LUN number can bedetermined in accordance with the LUN field of the FCP CMND CDB (SCSICommand Descriptor Block).

Consequently, storing the PLOGI information from the host and the volumeSCSI command access status in the storage apparatus makes it possible toacquire corresponding relationship information as to which host portsare accessing which volumes. This information can also be used to createthe target zoning information needed for accessing themigration-destination volume of the migration-destination storageapparatus.

Furthermore, host port and storage port security authenticationinformation, which is typified by a FC-SP (Fibre Channel SecurityProtocol), can also be used. The port name identifier of the hostaccessing the volume is clear even in a case where this port nameidentifier has been configured in either the target port or volume ofthe migration-source storage apparatus. Therefore, the target zoninginformation, which is registered in the fabric from the target port ofthe storage apparatus, may be created using the FC-SP authenticationinformation.

FIG. 27 is a flowchart showing an entire first operation for the storageapparatus port to configure the zoning information in the fabric. A stepwill be abbreviated as S in the drawing.

As the initial configuration, either the storage administrator or the FCfabric administrator grants the storage apparatus port permission tocontrol target zoning (510). S10 can be executed using multiple methods.One is a method in which the storage administrator configures thesecurity code, which allows access to the fabric, in the storageapparatus port. The other is a method in which the FC fabricadministrator registers the WWPN of the storage apparatus that is ableto configure the target zoning in a switch.

The storage apparatus port, subsequent to logging in to the fabric,configures the zoning information in the fabric (S11). As describedhereinabove, the zoning information is a list, which describes the portWWPN of the host that is able to access a volume belonging to thestorage apparatus port.

A message format, which is exchanged with the fabric, conforms to theformats shown in FIGS. 41 and 42. The exchange of messages whenregistering the zoning information in the fabric will be described indetail further below. The configurations and creation method of thezoning information sent by the storage apparatus are as described inFIG. 26( a) and FIG. 26( b).

Next, of the multiple switches (FDF 20) in the fabric, the switch thatreceived the zoning information changes the WWPN included in this zoninginformation to the N_Port ID, and distributes the post-change zoninginformation throughout the entire fabric (S12). Each of the otherswitches, which have received the zoning information, uses this zoninginformation to configure a zone. This makes it possible to carry outaccess control based on the D_ID-S_ID pair, which was explained usingFIG. 8( a) and FIG. 8( b) (S12).

FIG. 28 is a flowchart showing an entire second operation. In theprocessing of FIG. 28, when a host group is created by theadministrator, the storage apparatus creates the zoning informationbased on this host group. In this process, the zoning information isconfigured in the target port when the administrator configures the hostgroup information.

The administrator creates a host group in the storage apparatus (S20).The administrator configures in the entry C32 of the host groupinformation T30 a list of WWPNs of initiator ports that are allowed toaccess the volume (S21). This initiator port is the initiator port ofthe host 30 that is allowed to access the volume.

The administrator configures the LUN number of the volume in the entryC33 of the host group information T30, and, in addition, configures theLUN number for when the host is allowed to see the volume in the entryC34, and associates the two LUN numbers (S22).

When the administrator completes the configuring from S20 through S22,the storage apparatus creates the zoning information T40 based on thehost group information T30 (S23). That is, the storage apparatusassociates the storage apparatus target port with the WWPN list of hoststhat are allowed access, and creates basic information capable of beingused in fabric zone control.

When the storage apparatus port (target port) logs in to the fabric, S11and S12, which were explained using FIG. 27, are carried out. Inaccordance with this, the zoning information is distributed throughoutthe fabric. Since zone control is executed by the fabric afterdistribution has been completed, the host can only access an allowedvolume of an allowed storage port based on the fabric zoning informationand the storage host group information.

In the processing up to this point, the only step that must beconfigured by the fabric administrator is the one that grants thestorage apparatus port permission to configure the zoning described inS10 of FIG. 27.

This S10 is a process that is only required when the storage apparatusport is introduced, and is a step that is carried out before creatingthe volume. Therefore, there is no need for the fabric administrator andthe storage administrator to cooperate with one another. Accesspermission in a unit comprising the host port, the network, the storageport, and the volume can be carried out in batch fashion by configuringonly the storages. Therefore, the fabric administrator and the storageadministrator need not carry out cooperative management, therebyenabling the management burden on the computer system to be reduced.

FIG. 29 is a flowchart showing an entire third operation. In thisprocess, when the volume is migrated between the storage apparatuses,the migration-destination storage apparatus acquires the zoninginformation in the migration-source storage apparatus, and creates newzoning information.

Either the administrator or the management program of the managementserver 70 issues an instruction for the migration of the volume betweenthe storage apparatuses. The management program monitors and manageseach storage apparatus in the computer system. The explanation willfocus on a case where the instruction is issued by the managementprogram.

The management program instructs the migration-destination storageapparatus as to the number of the migration-source storage apparatusvolume (migration-target volume) and the number of the port that can beused by the migration-source storage apparatus for migration. Variousmethods for instructing the migration of the volume are conceivable, andany method may be used as long as the method does not impede theoperation of this embodiment.

The initiator port of the migration-destination storage apparatus mustcommunicate with the target port of the migration-source storageapparatus. Consequently, the migration-destination storage apparatuscreates zoning information, which associates the WWPN of themigration-destination storage apparatus initiator port with the WWPN ofthe migration-source storage apparatus target port. This zoninginformation is volume migration zoning information. The initiator portof the migration-destination storage apparatus registers the volumemigration zoning information in the FC fabric (S30). In accordance withthis, a communication path is established for the exchange of databetween the migration-target volume 43 of the migration-source storageapparatus and the virtual volume 43V of the migration-destinationstorage apparatus.

The migration-destination storage apparatus acquires zoning informationrelated to the migration-target volume 43 from the migration-sourcestorage apparatus (S31). This zoning information defines a paircomprising the host port that is allowed access to the migration-targetvolume, and the port of the migration-source storage apparatus.

For ease of understanding, the zoning information in themigration-source storage apparatus may be called the migration-sourcezoning information. The zoning information created in themigration-destination storage apparatus may be called themigration-destination zoning information.

There are at least two methods for the migration-destination storageapparatus to acquire the migration-source zoning information of themigration-source storage apparatus: a fabric acquisition method and amigration-source storage apparatus acquisition method.

In the former method, the migration-destination storage apparatus readsother zoning information that has been configured in the fabric.However, it is supposed that any port is allowed to read the otherzoning information from the fabric. In the latter method, themigration-destination storage apparatus takes over the migration-sourcezoning information associated with the migration-target volume of themigration-source storage apparatus. Either method may be used.

Next, the initiator port of the migration-destination storage apparatus,which is used as the data communication path, acquires and takes overvolume identification information (World Wide LU Name) of themigration-target volume via the migration-source storage apparatustarget port (S32).

The volume identification information is a concatenation of thedesignator information of FIG. 13( a) (example: an ASCII characterstring informing the manufacturer name) and the logic unit serial number(ASCII character string) uniquely assigned to each physical volume ofFIG. 13( d).

The migration-destination storage apparatus allocates the host groupinformation, the zoning information, and the volume identificationinformation that must be taken over to the virtual volume related to themigration-target volume (S33). In addition, the migration-destinationstorage apparatus associates the virtual volume with themigration-target volume (S33).

The migration-destination storage apparatus overwrites the target portnumber described in the migration-source zoning information with thetarget port number of the migration-destination storage apparatus,creates the migration-destination zoning information, and registers thismigration-destination zoning information in the fabric (S34).

The host path is switched from the migration-target volume of themigration-source storage apparatus to the virtual volume of themigration-destination storage apparatus (S35). Multiple host pathswitching methods are conceivable. One method issues instructions sothat the migration-destination storage apparatus notifies the managementserver 70 of the completion of the volume migration, and the managementserver 70 switches the access destination to the host. The other methodis a method in which either the migration-destination storage apparatusor the migration-source storage apparatus notifies the host to theeffect that the volume migration is complete and causes the host accessdestination to be switched.

For example, even a method that uses SCSI ALUA (Asynchronous LogicalUnit Access) to send an Active Port-Standby Port switchover message tothe host port from the storage apparatus is okay. The path switchoverinstruction may be carried out by any of the management server, themigration-source storage apparatus, or the migration-destination storageapparatus.

The association of the virtual volume and the migration-target volume(S33) will be explained further. For example, in one method, an I/Orequest to the virtual volume received from the host is transferred tothe migration-target volume by way of the migration-destination storageinitiator port and the zone provided for migration. In another method,either the migration-source storage apparatus or themigration-destination storage apparatus copies the data of themigration-target volume to the virtual volume. In yet another method,the configuration may be such that the migration-destination storageapparatus mounts the migration-target volume to the virtual volume.Another method may also be used.

When preparations for migrating the volume are complete, the path overwhich the I/O request from the host is to be sent is switched from themigration-source storage apparatus to the migration-destination storageapparatus in conjunction with the host path switchover (S35).

In accordance with the steps explained using FIG. 29, themigration-destination storage apparatus updates the fabric zoneconfiguration at the time of a volume migration between storageapparatuses.

However, there may be cases in which the zone configured between themigration-source storage apparatus and the host becomes unnecessaryafter the volume migration has been completed.

In this case, using the same thinking employed in the steps by which themigration-destination storage apparatus creates the zoning informationand registers this zoning information in the fabric, themigration-source storage apparatus is able to update themigration-source zoning information and register this updated zoninginformation in the fabric. That is, the migration-source storageapparatus updates the migration-source zoning information by deletingthe information of the unnecessary host, and registers the updatedmigration-source zoning information in the fabric. This makes itpossible to nullify the zone between the deleted host and the targetport of the migration-source storage apparatus.

As described hereinabove, both the zone configuration related to theport of the migration-destination storage apparatus, and the zoneconfiguration related to the port of the migration-source storageapparatus can be all carried out on the storage side. The fabricadministrator does not have to change the configuration of the fabricwhen a volume is created or a volume is migrated.

FIG. 30 is a flowchart showing an entire fourth operation. In thisprocess, the migration-destination storage apparatus acquires the hostgroup information of the migration-source storage apparatus, andmigrates the volume after creating zoning information from this hostgroup information.

FIG. 31 shows an entire fifth operation. In this process, themigration-source storage apparatus sends the host group information tothe migration-destination storage apparatus. The migration-destinationstorage apparatus creates target zoning information from the host groupinformation and migrates the volume. FIGS. 30 and 31 will be explainedby focusing on the parts that differ from the explanation of FIG. 28.

Refer to FIG. 30. The part of this process related to the creation ofthe zoning information differs from the process shown in FIG. 29.

A zone for data communications between storages is configured betweenthe migration-source storage apparatus and the migration-destinationstorage apparatus (S40). The migration-destination storage apparatusacquires the host group information and the volume identificationinformation from the migration-source storage apparatus (S41).

The migration-destination storage apparatus creates zoning informationfor use in the migration-destination storage apparatus based on the hostgroup information to which the migration-target volume belongs (S42).

Thereafter, the processing is the same as the processing of FIG. 29. Themigration-destination storage apparatus allocates the host groupinformation and the volume identification information to the virtualvolume (S43) and migrates the volume (S44). The migration-destinationstorage apparatus registers the zoning information(migration-destination zoning information) created in S42 in the fabric(S45). The host path is switched from the migration-source storageapparatus to the migration-destination storage apparatus (S46).

Refer to FIG. 31. The part of this process related to the creation ofthe zoning information also differs from the process shown in FIG. 29.Since S50 and S52 through S56 are the same as S40 and S42 through S46shown in FIG. 30, explanations thereof will be omitted.

In this process, the migration-source storage apparatus sends the hostgroup information to which the migration-target volume of themigration-source storage belongs to the migration-destination storageapparatus (S51). Furthermore, instead of this, the configuration mayalso be such that the migration-source storage apparatus creates thezoning information (the list of initiator port WWPNs of the host thatrequires access permission), and sends this zoning information to themigration-destination storage apparatus.

Example 2

A second example will be explained by referring to FIGS. 32 through 38.In this example, the operation of the fabric, which has received zoninginformation from a storage apparatus port, will be explained. Theexplanation will focus on the differences with the first example.

FIG. 32 is an example of the configuration of a virtual domain 550 in aFCoE fabric.

This configuration is a specific example of the abstract networktopology shown in FIG. 3.

The arrows, which couple the respective ports of FIG. 32, denote FCoEvirtual links rather than physical connections. The physical connectionshave been omitted from the description. The physical connections arebetween FCF MAC (physical Ethernet ports) disposed in either the FCF orthe FDF.

In FIG. 32, a total of four switches, two FCFs 10 and two FDFs 20, formvirtual links with one another. A FCF MAC of the primary FCF A, a FCFMAC of the secondary FCF A, a FCF MAC of a FDF A, and a FCF MAC of a FDFB are coupled to the same network. The FDF B and a FDF C are coupled toa network that differs from the network described above. For thisreason, the FCF A can access the FCF C via the FCF B.

Virtual links 503 and 504 are for controlling the primary FCF A and thesecondary FCF A, and the FDF A and the FDF B. The virtual link 503respectively couples the primary FCF A to the FDF A and the FDF B. Thevirtual link 504 respectively couples the secondary FCF A to the FDF Aand the FDF B.

The virtual links 503 and 504, specifically, are paths used whentransferring login information from the respective E_Nodes to the FCF.In addition, the virtual links 503 and 504 are paths used by the FCF toallocate a virtual domain number to a FDF, to distribute routinginformation, and to distribute zoning information. The FCF and a FDF, ora FDF and a FDF are coupled by a VA_Port.

A virtual link 505 is a redundant path that is used for synchronizingthe information of the primary FCF A with the secondary FCF A. Theprimary FCF A information and the secondary FCF A information aresynchronized for making the control with respect to the virtual domain550, which is the range of FCF control, redundant.

A virtual link 501 is a path used for communicating data between FDFsand for communicating control information without going through the FCF.A virtual link 502 is a path for either allowing communications betweenthe E_Node and the FDF, or allowing communications between a VN_Port anda VF_Port, which have been instantiated by the E_Node.

A control message 506 represents a message request for the storageapparatus port to register zoning information in the FDF. Furthermore,in FIG. 32, the configurations of the storage apparatus, the host, andthe VN_Port have been either simplified or omitted.

A flowchart of FIG. 33 shows a process for distributing by FDF targetzoning information (hereinafter, zoning information) received from thestorage apparatus to the other FDFs after the names have been resolvedby the FCF. Simply stated, name resolution is a process for converting aWWPN in the zoning information to a N_Port ID.

The virtual domain 550, to which the FDF that receives the zoninginformation from the storage apparatus belongs, is controlled by aprimary control FCF—secondary control FCF pair. The primary control FCFof this pair comprises control owner rights. Consequently, the primarycontrol FCF that controls the FDFs will be described as the “samevirtual domain FCF” hereinbelow, and an explanation thereof will beomitted.

The flow of processing up until the FCF and FDF form the virtual domain550 will be explained preliminarily. This description is the procedurerequired for initialization between the FCF and FDF switches. FIG. 33 isa flowchart related to a node-switch initialization procedure and zonedistribution, and as such, does not provide a description related to theswitch initialization procedure.

The FCF fabric configuration server 104 searches the respective FDFs andallocates the same virtual domain number to each FDF. The virtual domain550 shown in FIG. 32 is formed in accordance with this.

Each FDF registers the virtual domain number in the virtual domaindatabase 201 through the message transfer program 204. Pairs comprisingthe FCF and multiple FDFs are formed in the virtual domain in accordancewith this.

Next, the FCF fabric configuration server 104 allocates a range ofassignable N_Port IDs (N_Port ID Range: referred to as the subnet maskin IP) to each FDF, and registers the allocated information in thedatabase 103.

Each FDF stores the N_Port ID range allocated to the other FDF in thevirtual domain database 201, and, in addition, registers the rule foreach FDF VA_Port to the other FDF.

In the procedure described above, each piece of information held by theprimary control FCF is sent to the secondary control FCF via a virtuallink 287, and the information is synchronized between the respectiveFCFs. Therefore, even when a failure occurs in the primary control FCF,the secondary control FCF assumes control, and the scope of a failure'simpact is minimized.

The flowchart of FIG. 33 will be explained. Either the host E_Node orthe storage apparatus E_Node logs in to the VF_Port of the FDF, which isa switch comprising the FCoE fabric (S60). The FDF transfers the logininformation received from the E_Node to the same virtual domain FCF(S60).

The FCF processes the login request from the E_Node received from theFDF (S61). When the E_Node logs in to the VF_Port of the FDF, the FCFname server 102 allows the creation of a VN_Port instance correspondingto the E_Node-requested WWPN.

The name server 102 assigns the N_Port ID used in the FC Frame D_ID/S_IDshown in FIG. 8( a) to the VN_Port. The FCF name server 102 registers apair comprising the WWPN and the allocated N_Port ID in the name serverdatabase 101. The FCF returns the login request transferred from the FDFto the transfer-source FDF. The N_Port ID allocated to the WWPN is alsoincluded in the return (login response).

The FDF, upon receiving the login response, respectively registers theinformation of the WWPN related to the E_Node under the FDF and theN_Port ID allocated by the FCF to the N_Port allocation database 201.The FDF VF_Port returns the login response to the request-source E_Node.

The FDF VF_Port 22 receives zoning information from the storageapparatus port (562). Specifically, the FDF VF_Port 22 receives amessage called a Register Peer Device based Port Name (RPD_PN). Thismessage is exchanged in accordance with the FC Common Service CT_IUpayload. The formats of the RPD_PN request and response will bedescribed further below using FIG. 41.

The FDF queries the FCF name server 102 for converting the zoninginformation received from the storage apparatus from the WWPN to theN_Port ID (S63). For example, the FDF sends the list of WWPNs in theRegister Peer Device based Port Name (RPD_PN) to the FCF. The FDFreceives the N_Port ID corresponding to the WWPN from the FCF.

The FCF must propagate the zoning information to the FCF and FDF insidea different domain to which another domain number has been assigned. Forthis reason, the FCF registers this zoning information in the database1050 as virtual domain local zoning information distributed via the FDF.

The FDF is in receipt of the RPD_PN request from the VN_Port that islogged in to the FDF VF_Port 22, and as such, registers this RPD_PNrequest in the FDF local database 2030 as the FDF local zoninginformation (S63).

The FDF selects the zoning information to be registered in the other FDFfrom the N_Port ID information of the RPD_PN from among the informationregistered in the local database 2030 of the zone database 203, and theN_Port ID range of the other FDF being stored in the virtual domaindatabase 202. The FDF distributes the selected zoning information to theother FDF (S64). The FDF returns a RPD_PN response to the VN_Port.

FIG. 34 is a ladder chart denoting the exchange of messages in theflowchart of FIG. 33. The respective step numbers of FIG. 33 match withthe step numbers described in the ladder chart of FIG. 34. Therefore, nofurther explanation will be given.

As described above, since the FDF distributes the zoning information tothe other FDF, the FCF need not distribute the zoning information tosubordinate FDFs.

A large number of volumes 43 are associated with the storage apparatusport, and the respective virtual servers 33 and volumes 43 areassociated in accordance with the host group of the storage apparatus.Therefore, a large number of hosts are associated with the zoninginformation registered in the target port of one storage apparatus.

In addition, the physical server 30 where the virtual machine residesand the physical storage apparatus 40 of the volume migrationdestination are dispersed inside the fabric in line with either themigration of a virtual machine or a volume migration between storageapparatuses. Therefore, the virtual server and the storage apparatuscommunicate via multiple switches.

For this reason, when the storage apparatus registers the zoninginformation in the switch (FDF), the zoning information must bedistributed to substantially all the FDFs in line with the migration ofthe virtual machine.

In a case where the distribution of the zoning information is entrustedto the FCF, transactions will increase in accordance with the number ofFDF switches, the number of virtual servers, the number of physicalports in the storage, the number of virtual ports in the storage, andthe number of virtual volumes. By contrast, in this example, the FDF,which received the zoning information from the storage apparatus,distributes this zoning information to the other FDFs, thereby reducingthe transactions for zoning distribution.

Furthermore, to simplify the explanation, the description stated thatthe FDF distributes the zoning information received from the storageapparatus to the other FDFs. However, in actuality, the FDF createsinformation for zone control based on the zoning information receivedfrom the storage apparatus, and distributes this zone controlinformation to the other FDFs.

The flowchart of FIG. 35 shows another process for distributing thezoning information to the FDFs. In this process, login information ofthe FCF is distributed in advance to the FDF in the virtual domain, andthe zoning information received from the storage apparatus undergoesname resolution in the FDF and is distributed to the other FDFs. Sincethe explanation of this process duplicates the explanation of FIG. 31,the differences will be explained.

When the E_Node logs in to the FDF VN_Port, the FDF transfers the loginrequest to the FCF the same as in S60 (S70).

The FCF assigns a N_Port ID to the login request received from the FDF.The FCF notifies all the FDFs belonging to the virtual domain that theN_Port ID has been allocated to the login request (S71). The differenceswith S61 of FIG. 33 are that the WWPN and N_Port ID information isdistributed to all the FDFs rather than just to the FDF, whichtransferred the login request, and the information of the respectiveFDFs is synchronized. In accordance with this, each FDF has a nameserver database 101 related to the name server for the entire virtualdomain. Therefore, each FDF can respectively execute the name resolutionfrom the WWPN to the N_Port ID, making queries to the FCF unnecessary.

In S72, the zoning information is received from the storage apparatusport the same as in S62 of FIG. 33.

As described above, each FDF also stores information about the othernodes in the virtual domain. Therefore, the FDF that receives the zoninginformation from the storage apparatus converts the WWPN list includedin this zoning information (RPD_PN) from the WWPNs to the N_Port IDs(S73).

In addition, because the FDF, which rewrites the WWPN list as the N_PortID list, also comprises the N_Port ID range information of the otherFDFs in the virtual domain, this FDF distributes the rewritten zoninginformation to the other FDFs (S74).

The difference between this process and the process shown in FIG. 33 isthat after receiving the zoning information from the storage apparatusport, the FDF does not have to query the FCF until the distribution ofthe zoning information to the FDFs is complete. Subsequent to zoneconfiguration completion, a state change notification is sent to thenode (S75) and the completion of zone configuration is conveyed.

FIG. 36 is a ladder chart denoting the exchange of messages in theflowchart of FIG. 35. The respective step numbers of FIG. 36 match withthe step numbers cited in the message ladder chart of FIG. 35. For thisreason, further explanations will be omitted. Comparing the nodeprocessing parts of the ladder chart of FIG. 34 with the node processingparts of the ladder chart of FIG. 36 reveals that node wait time isshortened delta T. The wait time is the time that the node spendswaiting for the completion of the zone distribution to the FCF and FDFs.

After sending the zone distribution (RPD_PN) request of S72, the FDFimmediately returns a response to the node as indicated by thedashed-line arrow. By contrast, in FIG. 34, the response with respect tothe request of S62 is returned to the node from the FDF in S65.

Since wait time is shortened, the node can execute another process. Inaddition, because wait time is shortened, there is less likelihood of atimeout error occurring in the node, thereby improving usability.

In a case where a virtual resource (a volume or virtual machine) isfrequently migrated within the computer system, it becomes necessary torespectively carry out a process for logging out of the fabric, aprocess for propagating zone nullification to the FDFs, a process forlogging in to the fabric at the migration destination, and a process forconfiguring a new zone. Therefore, the reliance on the FCF for nameresolution concentrated the control load in the FCF.

Alternatively, because each FDF can function as a name server in thisexample, it is possible to prevent the concentration of traffic relatedto zone configuration and the distribution of zoning information in theFCF. In addition, as was described hereinabove, since the node wait timecan be reduced, the RPD_PN response can reduce the likelihood of atimeout. Therefore, a computer system comprising a relatively largefabric and a relatively large number of virtual resources can beoperated stably.

FIG. 37 is an example of the configuration of the fabric in FIG. 32 whenmultiple virtual domains exist. The differences with FIG. 32 are thatthere are two control FCFs, each of which having a different virtualdomain. A virtual link 510 couples the FCF A VE_Port to the FCF BVE_Port. The virtual link 510 is a ISL (Inter Switch Link) for couplingdifferent domains.

FIG. 38 is a ladder chart for a FDF to distribute zoning informationreceived from the storage apparatus to the FCF and FDFs in the fabrichaving multiple virtual domains shown in FIG. 37. The explanation willfocus on the differences between FIG. 33 and FIG. 35.

When the node belonging to the one virtual domain A logs in to theVF_Port of the FDF AA (S80), the login request is sent to the FCF A thatmanages the virtual domain A (S81). The FCF A returns the N_Port ID tobe allocated to the node (S81).

When the node sends the zoning information to the FDF A (S82), this FDFA distributes the zoning information to the other FDFs (not shown in thedrawing) in the virtual domain after converting the WWPN to the N_PortID. The zoning information is also distributed to the FCF A (S83).

When the distribution of the zoning information within the virtualdomain A is complete, the FCF A exchanges a request (MR: Merge Request)for merging the zoning information with the other virtual domain B viathe inter switch link 510 (S84).

The FCF B distributes the zoning information received from the FCF A tothe FDFs in the virtual domain B (S85). The FCF A notifies the node ofthe state change (S86).

After the node registers the FC-4 type and so forth with respect to thename service (S87, S88), the FCF A notifies the other domain as to thestate change (S89). The FCF B, which manages the notified domain,queries the name server database and the fabric configuration serverdatabase (S90).

Specifically, the FCF B acquires a list of port states using a GPL (GetPort List), and acquires a list of port names of the VN_Port, for whichthe FC-4 type is the SCSI FCP protocol, in accordance with a GE_PT (GetEntry based Port Type) (S90).

The problem of domain numbers being used up the more resources there arein the fabric as a whole is known, but the consumption of the number ofdomains can be reduced by increasing the size of the virtual domain to acertain extent. In this example, the time required to merge the zoninginformation between the domains can be reduced.

Example 3

A third example will be explained by referring to FIGS. 39 through 42.FIG. 39 is a flowchart showing a process for collectively distributingzoning information in a case where the FDF receives login requests frommultiple FCoE nodes (E-Nodes). Since this process is equivalent to avariation of the process shown in FIG. 33, the explanation will focus onthe differences with FIG. 33.

S100 is the same as S60 of FIG. 33. However, in S100, a case in which alogin request is simultaneously generated from another node is alsotaken into account. Furthermore, S101 is the same as S61 of FIG. 33.

S102 is the same as S62 of FIG. 33. However, in S102, login requests arereceived from each of multiple nodes.

Next, the FDF merges the zoning information received from multiplenodes, and collectively queries the FCF about the collected zoninginformation (S103). This query has the same content as that explained inS63 of FIG. 33.

The FDF merges the multiple pieces of zoning information and distributesthis information to the other FDFs that are in need thereof the same asin S64 of FIG. 33 (S104). Lastly, the FDF notifies the node (storageapparatus) to the effect that the distribution of the zoning informationhas been completed the same as in S65 of FIG. 33 (S105).

FIG. 40 is a ladder chart denoting the exchange of messages in theflowchart of FIG. 39. The respective step numbers of FIG. 39 match thestep numbers listed in the messages of the ladder chart of FIG. 40. Forthis reason, no further explanation will be given.

In this example, the FDF merges multiple query requests to collectivelyquery the FCF (S103 and S104), thereby further lessening the load on theFCF.

In addition, in this example, it is possible to collectively distributeby the FDF the zoning information received from each of multiple nodeswhen distributing the zoning information to the other FDFs. Therefore,the transactions for distributing the zoning information among the FDFscan be reduced.

FIG. 41 shows a Register Peer Device based Port Name (RPD_PN) format,which is a zoning information request message.

FIG. 41( a) is a request format. FIG. 41( b) is a portion of the entryof FIG. 41( a). The RPD_PN is exchanged in accordance with the FC CommonService CT_IU payload.

In a case where the switch authentication explained using the flowchartof FIG. 27 is necessary, a common header, which is called the first 4DW(Double Word) CT_IU Preamble, can be replaced with an extension header,and an authentication code can be added. This inhibits a malicious portfrom changing the zoning of the fabric on its own and generating anunauthorized access.

The format of FIG. 41( a) has a number of WWPN entries, a flag foridentifying whether a requestor is an initiator or a target, and a list87. The list 87 stores the list shown in FIG. 41( b). The format shownin FIG. 41( b) has a WWPN field, which grants the requestor portpermission to communicate.

FIG. 41( c) is the format for the RPD_PN response. FIG. 41( d) is aportion of the entry of FIG. 41( c). The format of FIG. 41( c) has anumber of list entries, and a list 88. The list 88 stores the list shownin FIG. 41( d).

The format of FIG. 41( d) has a WWPN field, which grants the requestorport permission to communicate, a N_Port ID field for the nameresolution from the WWPN in a case where this fabric has logged in, anda flag showing that login is complete.

In the case of an embodiment (control method of FIG. 35) in which nameresolution is not required, the number of list entries and the list 88are not needed in the RPD_PN response format.

FIG. 42 shows the formats of Get Peer Name based Port Name request andresponse formats for acquiring zoning information from the fabric. FIG.42( a) shows the request format. FIG. 42( b) shows the response format.

The RPD_PN is exchanged in accordance with the FC Common Service CT_IUpayload. The WWPN 89 of the originator (another port) is stored in theformat of FIG. 42( a) to acquire zoning information configured byanother port from this other port.

The zoning information registered in accordance with the originator WWPNof FIG. 42( a) with respect to the request of FIG. 42( a) is returnedusing the format of FIG. 42( b). The format of FIG. 42( b) has a numberof permission WWPN list entries registered with respect to theoriginator WWPN, and a field for a permission WWPN list 90 with respectto the originator WWPN. Multiple entries of the format explained usingFIG. 41( b) are stored in the permission WWPN list 90.

The messages shown in FIG. 42 are used when acquiring zoning informationfrom the fabric as explained using FIG. 29. In addition, a messageformat for collectively acquiring the configurations of the zoninginformation for the fabric as a whole is also conceivable. Since thiskind of format can easily be inferred from FIG. 42, an explanation ofthis format will be omitted.

The effects shared in common by the first example through the thirdexample will be explained further. FIG. 43 is a ladder chart showing howto distribute zoning information sequentially among the fabric switches.In the prior art, the FC fabric administrator manually registered thezoning information between the host and the storage apparatus in thefabric one at a time.

For this reason, either the FCF or the FC domain switch stores thezoning information. To distribute zones to all the domain switches thatcomprise the fabric, MRs (Merge Requests) must be exchanged betweenadjacent switches as shown in FIG. 43. The exchange of MRs generatestraffic corresponding to the square of the number of domain switches.

This makes it difficult to increase the number of domain switches.Alternatively, in the embodiment explained using FIGS. 32 through 42, itis possible reduce the number of domain switches (FCF). Therefore, MRcontrol traffic can be reduced, and, in addition, the downtimeaccompanying the re-changing of zones in the fabric as a whole can beshortened.

FIG. 44 is a ladder chart of a case in which the control FCF distributesthe zoning information held by the control FCF to the respective FDFs.

The fabric administrator configures a zone in the FCF beforehand (S200).When a node logs in to the FDF A (S201), the FDF A transfers the loginrequest to the FCF (S202).

The FCF, which controls the virtual domain, distributes the zone to allthe FDFs based on the name server database (S203 through S205). Lastly,the FCF returns a login response to the node after zone configurationhas been completed (S206).

As shown in FIG. 44, merging is not possible in a case where multiplenodes issue login requests when the zones are being centrally managed bythe FCF. In addition, there is also the possibility of a login requesttimeout occurring in the node due to the login response being returnedafter zone distribution has been completed (S206).

In addition, when a duplicate login is carried out, there is thelikelihood of a Resource Allocation Timeout (R_A_TOV) occurring,resulting in a 10 second wait. Therefore, there will be cases in whichthe migration of a virtual resource over a short period of time willfail, making stable system operation difficult.

Alternatively, in this embodiment, multiple login requests can be mergedand sent to the FCF, making it possible to reduce control traffic. Inaddition, it is also possible to prevent the occurrence of timeoutsduring the login request process.

Furthermore, the present invention is not limited to the above-describedembodiment. A person with ordinary skill in the art will be able to makea variety of additions and changes without departing from the scope ofthe present invention.

For example, the present invention can be understood as a switch. Thisswitch, for example, can be expressed as follows:

-   -   “(First Aspect) A fabric comprising multiple coupled switches,    -   wherein the above-mentioned multiple switches comprise a first        switch, and multiple second switches, which are managed by the        above-mentioned first switch,    -   of the above-mentioned multiple second switches, a prescribed        second switch, which receives from a first node (for example, a        storage apparatus) access control information related to a        second node (for example, a host computer) capable of accessing        the above-mentioned first node, sends and registers the        above-mentioned access control information in each of the other        second switches of the above-mentioned multiple second switches.    -   (Second Aspect) A fabric according to the first aspect, wherein        the above-mentioned prescribed second switch requests that the        above-mentioned first switch rewrite a portion of the        above-mentioned access control information, and sends and        registers the rewritten access control information in each of        the above-mentioned other second switches.    -   (Third Aspect) A fabric according to the second aspect, wherein,        in a case where access control information has been received        from each of multiple first nodes, the above-mentioned        prescribed second switch sends this access control information        to the above-mentioned first switch and requests that each piece        of the above-mentioned access control information be rewritten.    -   (Fourth Aspect) The above-mentioned prescribed second switch        comprises a name server function, rewrites the WWPN inside the        above-mentioned access control information received from the        above-mentioned first node to a N_Port ID, and sends and        registers the rewritten access control information in each of        the above-mentioned other second switches.    -   (Fifth Aspect) An information management method for a fabric,        which comprises multiple coupled switches,    -   wherein the above-mentioned multiple switches comprise a first        switch, and multiple second switches, which are managed by the        above-mentioned first switch,    -   the above-mentioned fabric information management method        comprising the steps of:    -   the above-mentioned first switch managing information that is to        be managed centrally inside the fabric; and    -   the above-mentioned each second switch respectively managing        other information besides the above-mentioned centrally managed        information.    -   (Sixth Aspect) A fabric information management method according        to the fifth aspect, wherein the above-mentioned each second        switch, in a case where the above-mentioned other information        managed by its own apparatus is changed, sends this changed        above-mentioned other information to each of the other second        switches other than its own apparatus, and updates the        above-mentioned other information stored in the above-mentioned        each other second switch.”

In addition, the present invention can also be understood as a storageapparatus. This storage apparatus, for example, can be expressed asfollows:

-   -   (First Aspect) A storage apparatus, which is coupled to a host        computer via a FC (Fibre Channel) fabric, comprising:    -   a storage port, which is coupled to a host port of the        above-mentioned host computer,    -   wherein, based on a first information associated with access        control for controlling access to the relevant storage apparatus        by the above-mentioned host computer, creates a second        information, which defines the above-mentioned host computer        that is able to access the relevant storage apparatus, and    -   registers the created above-mentioned second information in the        above-mentioned fabric.    -   (Second Aspect) A storage apparatus according to the first        aspect, wherein it is possible to receive a portion of logical        volumes from among multiple logical volumes associated with a        certain storage port inside another storage apparatus.

REFERENCE SIGNS LIST

-   -   10 FCF (first switch)    -   20 FDF (second switch)    -   30 Host computer    -   40 Storage apparatus

1. A computer system in which one or more host computers having a FC(Fibre Channel) node port and one or more storage apparatuses having aFC node port are coupled via a FC fabric, wherein the storage apparatus:acquires first information related to access control for controllingaccess to a relevant storage apparatus by the host computer; creates,based on this first information, second information for defining thehost computer that is able to access the relevant storage apparatus; andregisters the created second information in the fabric.
 2. A computersystem according to claim 1, wherein the storage apparatus comprises amigration-source storage apparatus, which constitutes a migration sourceof a migration-target resource, and a migration-destination storageapparatus, which constitutes a migration destination of themigration-target resource, and wherein the migration-destination storageapparatus: acquires the first information either directly or indirectlyfrom the migration-source storage apparatus; creates the secondinformation based on the acquired the first information; and registersthe created the second information in the fabric.
 3. A computer systemaccording to claim 2, wherein, in the migration-source storageapparatus, multiple logical volumes are associated with the FC nodeport, and a portion of the logical volumes from among these multiplelogical volumes can be migrated as migration-target volumes to themigration-destination storage apparatus, and the migration-destinationstorage apparatus acquires first information related to themigration-target volume from the migration-source storage apparatus. 4.A computer system according to claim 2, wherein the first information isfirst basic zoning information for defining, from among the hostcomputers, a host computer that is able to access the migration-sourcestorage apparatus, the second information is second basic zoninginformation for defining, from among the host computers, a host computerthat is able to access the migration-destination storage apparatus, andthe migration-destination storage apparatus creates the second basiczoning information by changing, from among the information included inthe first basic zoning information, information denoting amigration-source storage port of the migration-source storage apparatusto information denoting a migration-destination storage port of themigration-destination storage apparatus.
 5. A computer system accordingto claim 4, wherein the migration-destination storage apparatus readsthe first information from the migration-source storage apparatus.
 6. Acomputer system according to claim 4, wherein the migration-destinationstorage apparatus acquires the first information from the fabric.
 7. Acomputer system according to claim 4, wherein the migration-sourcestorage apparatus sends the first information to themigration-destination storage apparatus.
 8. A computer system accordingto claim 4, wherein the migration-target resource is a storage port, andmigrates a port name identifier of a migration-source storage apparatusto a storage port of a migration-destination storage apparatus.
 9. Acomputer system according to claim 4, wherein the migration-targetresource is a logical volume, and migrates a logical unit nameidentifier of a migration-source storage apparatus to a virtual logicalunit name identifier of a migration destination.
 10. A computer systemaccording to claim 9, wherein the migration-destination storageapparatus correspondingly manages a storage space of a migration-sourcelogical volume of the migration-source storage apparatus, and a storagespace of a migration-destination logical volume of themigration-destination storage apparatus, and carries out processing byconverting an access, from the host computer to themigration-destination logical volume, to an access from themigration-destination storage apparatus to the migration-source logicalvolume.
 11. A computer system according to claim 3, wherein the firstinformation is created as host group information for defining a logicalunit identifier inside a storage apparatus accessible to a port nameidentifier of the host computer, the second information is second basiczoning information for defining, from among the host computers, a hostcomputer that is able to access the migration-destination storageapparatus, and the migration-destination storage apparatus creates thesecond basic zoning information based on the host group information andinformation denoting the migration-destination storage port of therelevant migration-destination storage apparatus.
 12. A computer systemaccording to claim 11, wherein the migration-target resource is at leasteither a storage port or a logical volume.
 13. A computer systemaccording to claim 1, wherein the fabric comprises a first switch andmultiple second switches, which are managed by the first switch, thestorage apparatus sends the second information to a coupling-destinationsecond switch to which the relevant storage apparatus is directlycoupled, from among the respective second switches, thecoupling-destination second switch requests the first switch to convertthe identification information for identifying the host computerincluded in the second information, and creates, based on theidentification information converted by the first switch, thirdinformation for defining a host computer that is able to access thestorage apparatus, and moreover transfers and registers the createdsecond information in prescribed second switches of the respectivesecond switches.
 14. A method for managing a computer system, in whichone or more host computers and one or more storage apparatuses arecoupled via a FC (Fibre Channel) fabric, comprising the steps of: thestorage apparatus acquiring first information related to access controlfor controlling access to a relevant storage apparatus by the hostcomputer; the storage apparatus, based on the first information,creating second information for defining the host computer that is ableto access the relevant storage apparatus; and the storage apparatusregistering the created the second information in the fabric.